The experimental data come from ARPES studies using two different sources of light: high-energy light from synchrotron sources and lower-energy laser sources. In studies of high-temperature superconductors, these two light sources yield significantly different photoemission spectra for the same samples, and researchers have been unable to resolve this inconsistency. But Gweon and Shastry found that these apparently irreconcilable results can be accounted for by the same theoretical functions, with a simple change in one parameter.
"We can fit both laser and synchrotron data with absolute precision, which suggests that the two techniques are consistent with each other," Shastry said. "They are telling two different slices of the same physical result."